The Story of Nanomaterials in Modern Technology: An Advanced

In the Classroom

The Story of Nanomaterials in Modern Technology: An Advanced Course for Chemistry Teachers Ron Blonder Department of Science Teaching, Weizmann Institute of Science, Rehovot, 76100 Israel; [email protected]

Nanoscience is an important new scientific field. Nanotechnology is the ability to create materials, devices, and systems having fundamentally new properties and functions by working at the atomic, molecular, and supramolecular levels (1). These new properties are used as the basis for the development of new technology in electronics, magnetics, optoelectronics, medical diagnostics, alternative energy, and more. Roco emphasized the importance of education for the future developing of this field (2, p 1247): “One of the `grand challenges' for nanotechnology is education, which is looming as a bottleneck for the development of the field”. Incorporating Nanoscience and Nanotechnology in the Curriculum Trying to deal with this challenge led to the creation of many educational programs, curricula, and modules in nanotechnology. Walters and Bullen (3) developed a nanomaterials one-week intersession course, aimed at introducing students to nanomaterials through synthesis and characterization of nanomaterials and understanding the potential implications of nanomaterials on society. Samet (4) described a capstone course in nanotechnology for chemistry majors. This course was based on four laboratory projects. Porter (5) described a course that emphasized the interdisciplinary nature of nanoscience and nanotechnology. In a different work by Ambrogi et al. (6), high school students learned about nanotechnology and prepared a slide presentation to introduce nanochemistry and nanotechnology to younger students. Educational efforts to master nanoscience are needed to present this new science in such programs. Educators are faced with a problem: Most nanoscience researchers received their training in disciplines other than nanoscience, and are faced with difficulties when teaching nanoscience (7). Conversely, it is challenging for teachers to keep up-to-date on advanced topics such as nanoscience, as they completed their training before the advent of nanoscience, and will naturally find it difficult teaching content they do not know well (8). Our course was designed to provide teachers with basic concepts and knowledge in nanoscience, to arouse their enthusiasm for modern chemistry and its applications, and allow them to teach advanced topics in nanochemistry. Much literature on improving teaching and upgrading the professional status of teachers focuses on teachers' knowledge (9, 10). The idea of a knowledge base for teachers was derived from Shulman's categories of knowledge (11, 12). Shulman distinguished between three categories of teachers' knowledge: (i) subject matter content knowledge; (ii) pedagogical content knowledge (PCK); and (iii) curricular knowledge. Research findings on the effectiveness of teachers' professional

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development indicate the importance of their knowledge and professional enthusiasm. Many teachers in the education system completed their training over 10 years earlier. As a result, their science knowledge and acquaintance with important developments in science teaching is limited. To incorporate the three knowledge categories (content knowledge of nanoscience, pedagogical content knowledge, and curricular knowledge) into the structure of the course, our course was designed by a chemistry professor together with a science education researcher. Reshef Tenne, holder of the Drake Family Chair in Nanotechnology, Weizmann Institute of Science, and Director of the Helen and Martin Kimmel Center for Nanoscale Science teamed with the author, a researcher in the Department of Science Education at the Weizmann Institute of Science. Aims of the Course Introduction to Materials and Nanotechnology was designed to expose high school teachers to modern research topics, introduce teachers to nanoscience, generate teacher interest, and increase chemistry teachers' nanoliteracy by providing them with the basic principles of nanoscience. The course is structured accordingly: First, the instructor teaches fundamental knowledge essential to understand topics in nanoscience and advanced materials characterization. Then, the students (who are high school teachers) apply this knowledge while independently studying one topic that they select themselves. Here they integrate newly learned content with their PCK while presenting their selected topic to the other teachers and then writing a scientific report. Research lab experiments that follow provide the course participants with an additional opportunity for knowledge integration. Here they experience an authentic research experiment and apply their knowledge to the research methods and to understanding the results. Course Setting The course was part of a special M.Sc. program for science teachers, The Rothschild-Weizmann program for Excellence in Science Teaching, which will be described elsewhere. In this program, teachers participate in advanced courses related to their main field of teaching, courses in pedagogy, and courses in science education research. The current course, Introduction to Materials and Nanotechnology, was given as one of the advanced courses in chemistry. The lectures were given by Weizmann Institute faculty members specializing in the various subjects related to the course. Seven high school chemistry teachers studying for this special M.Sc. degree program and one M.Sc. chemistry student

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r 2010 American Chemical Society and Division of Chemical Education, Inc. pubs.acs.org/jchemeduc Vol. 88 No. 1 January 2011 10.1021/ed100614f Published on Web 10/27/2010

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Journal of Chemical Education

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In the Classroom

participated in this course. The 48-h course focused on the science content of materials and nanotechnology, and an additional 28 h focused on pedagogy and its connection to educational field. In this paper, we shall concentrate only on the scientific part of the course. Course Structure and Content Structure Rationale The first two modules;qualitative quantum mechanics, and advanced characterization methods in materials research; provide participants with the basic concepts of nanoscience. In the remaining modules, participants apply this acquired knowledge. The course's structure guides participants to connect physical principles, chemical materials, and technological applications in the field of nanoscience. This connection is implemented in subsequent modules: students in the course present lectures on selected topics in materials science and nanotechnology, and participate in authentic research in the laboratories of the Weizmann Institute. The fifth module, connection to education, focuses on the educational applications of nanoscience. Introduction The introduction was planned to give participants a general idea about the course and its aims. The first meeting began with a historical survey of material science from ancient times to present day, and an explanation on the structure of the course. This was followed by a brief description of 14 chosen topics in nanotechnology: blue (white) light-emitting diodes; ferroelectricity; carbon fullerenes and nanotubes; giant magneto-resistance; magnetic storage and spintronics; nano optoelectronics and nanosensors; nanocomposites; organic light-emitting diodes; photovoltaics; quantum dots; quasicrystals; shape memory alloys; superconductivity; and superhard coatings. These subjects, representing important research and technological applications, were chosen to provide participants with various options to choose from for their presentations, which they delivered later in the course. Module 1: Qualitative Quantum Mechanics On the basis of quantum effects, materials in the nanoscale acquire new properties. The first module of the course aims to provide participants with a background on quantum mechanics. The module opens by demonstrating that classical physics failed to address certain problems. Quantum mechanics provides an explanation and an alternative and comprehensive description for those unexplained physical phenomena. We discuss quantum mechanics as a wave theory, the Schrodinger equation, and selected predictions of the Schrodinger's equation. Finally, the connection between quantum mechanics and chemistry is emphasized by presenting chemistry as a many-electron quantum problem. This module is taught by L. Kronik, whose research focuses on the quantum theory of materials. Module 2: Characterization Methods The second module is designed to make the participants nanoliterate. Six characterization methods are introduced: scanning probe microscopy (AFM, STM); transmission electron microscopy (TEM); scanning electron microscopy (SEM); X-ray photoelectron spectroscopy (XPS); X-ray diffraction (XRD); and transport measurements. These methods were selected for 50


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two reasons: the importance of each method in nanoscience and the availability of the equipment and expertise at the Weizmann Institute. Each method is presented by a lecture and a visit to the corresponding laboratory. Both the lectures and lab visits are guided by the scientific staff member (senior research associate) who works with the equipment on a daily basis. The operating principles and the data that can be obtained using these methods are explained, and examples of real experimental results are discussed. In Modules 3 and 4 of the course, participants are required to read research papers and to understand experimental lab results. Module 3: Selected Advanced Topics in Materials Science and Nanotechnology Each student chooses a topic presented in the introduction. The course assignments were designed to have participants apply their understanding of the first two modules, as they were now more nanoliterate. After choosing a subject, participants receive a file of initial literature resources including three-four scientific papers and reviews on their chosen subject (as shown in the online supporting information). First, participants read about the topic, find additional scientific papers on the topic, and then write their questions. Next, the participants receive two kinds of personal guidance: general guidance, and scientific guidance. The general face-to-face guidance helps participants understand the scientific terms used in the papers, guides them during library searches for more papers in the relevant topic, and assists them in building a slide presentation. The scientific face-to-face guidance includes a discussion on the chosen scientific topic, focusing on individual participant's written questions. Participants present their topics as 50-min lectures followed by 10 min for general discussion. The topics chosen by the students are presented in Table 1 and appear as the first eight topics in the online supporting information. The subjects cover different aspects of nanoscience and different applications in electronic and optical properties, mechanical properties, energy, and magnetism. A list of the initial references for the different topics is presented in the online supporting information. The important criteria for choosing the subjects was the relevance to both materials science and nanotechnology in the broader sense of the word, and their relevance to contemporary science and technology. Students' Lectures Students in the course (high school teachers) present lectures on different topics in nanoscience, all sharing the same format. The lectures begin with the historical development of the topic, then proceed with the technological goals of that topic. Most of the lecture is devoted to the physical and chemical aspects of the topic and its technological applications. The summary includes relevant Israeli contributions to the specific subject, technological advances related to the topic, future expectations, and criticism. Each student also submits a written report at the end of the course. Module 4: Research Lab Experiments During the last scientific module, participants take part in two ongoing experiments in nanochemistry research labs, thus, performing authentic experiments together with the institute's chemistry research students. The first experiment is called Drawing with Nanotubes (13, 14). In this experiment, the

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r 2010 American Chemical Society and Division of Chemical Education, Inc.

In the Classroom Table 1. Structure for the Course: Introduction to Materials and Nanotechnology Course Modules 0. Introduction

Nanoscience and Nanotechnology Topics First look on nanotechnology A short description of 14 advanced topics in materials science and nanotechnology

Time Allotted

2h

1. Qualitative quantum mechanics

Difficulties with classical physics Quantum mechanics as a wave theory Schrodinger's equation Selected predictions of Schrodinger's equation Chemistry as a many-electron quantum problem

12 h

2. Characterization methods: Each of these methods was introduced through a lecture (2 h) and a lab demonstration (1 h)

AFM; STM;Atomic force microscope; Scanning tunneling microscope TEM;Transmission electron microscope SEM;Scanning electron microscope XPS;X-ray photoelectron spectroscopy XRD;X-ray diffraction Transport measurements

18 h

3. Students' lectures: Selected advanced topics in materials science and nanotechnology

Superconductivity Photovoltaic cells Light-emitting diodes (LED) Organic light-emitting diodes (OLED) Shape memory alloys Quantum dots Carbon fullerenes and nanotubes Nanocomposites

18 h

4. Research lab experiments

Drawing with nanotubes (13, 14) Electrospinning nanotube-reinforced composites (15, 16)

8h

5. Connection to education

How to write a scientific report The structure of a good presentation Transferring content to the teacher's classroom

28 h

students perform electrodeposition of gold on carbon nanotubes that are grown onto quartz substrates. They study the effect of gold ion concentration in solution on the resulting density and size of electrodeposited nanoparticles, using both optical microscopy and AFM. Participants also use AFM to check the diameter-size distribution of the nanotubes grown, using ferritin as a catalyst. The second experiment is called Electrospinning NanotubeReinforced Composites (15, 16). In this experiment, participants are introduced to the preparation and mechanical test of carbon nanotube (CNT)-reinforced composites. First, the participants are introduced to the principle of electrospinning and prepared electrospun poly(methyl methacrylate) (PMMA) fiber under high voltage (7 kV). They observe the resultant fibers collected on glass slides using optical microscope. The fibers have a high aspect ratio, that is, submicrometer diameters and lengths of a few centimeters. Second, they learn the principles of tensile tests and the meaning of the results, and watch videos of tensile tests of electrospun PMMA and PMMA/MWCNTs. Participants are then given dog-bone specimens of neat epoxy and of CNT-reinforced epoxy: they tensile-test the specimens and analyze the results. Module 5: Connection to Education Participants met among themselves every week for 2 h to discuss different aspects of nanochemistry. They were guided by the author, a researcher in science education who received her Ph.D. in chemistry in the field of nanochemistry (17). This module was presented throughout the entire course. The discussion was based on the participants' questions related to the course, and included three different types of


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questions: (i) questions about the scientific lecture contents; (ii) questions pertaining to the topics that were selected by the students and their presentations; and (iii) questions about the course's connection to teaching. This part of the course was continuously assessed by educational researchers and will be discussed elsewhere. Students' Responses to the Course After the introductory meeting, participants responded in two ways: they were excited to learn about the appealing subject of nanochemistry and also had some trepidation. Both sentiments are found in these comments from the first workshop they participated in (pseudonyms are used). Sara: I always wanted to know what nanochemistry is and about its applications. Shir: I tell my students that nanotechnology is an amazing field, but although I teach the program of nanotechnology in school, I am never quite sure that I understand it well enough.

Participants' enthusiasm was countered with deep concerns, and they expressed them: Yael: The course assignments, like preparing a lecture and writing a scientific report on a selected topic may be too difficult for us; I don't think that I am up to it.

After concluding the last course session, participants were asked to complete a questionnaire containing a knowledge test and requesting their feedback regarding the course. The knowledge test was given twice, at the beginning of the course and then again at its end. Participants were asked to explain a list of concepts related to nanochemistry. Comparing the participants'


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In the Classroom

that serve us in everyday research all over the world. I feel that you are now more literate than before... My hope is that you will transfer what you have learned here to your own students.

Science educators who would like to consider teaching this course in their institution are welcome to contact the author for additional details regarding the course and its curriculum. Acknowledgment

Figure 1. Profiles of students' knowledge in nanotechnology before participating in the course (PRE) and after it ended (POST), by nanoscience topic.

achievements in the pre- and posttests showed a remarkable improvement in their conceptual understanding of nanochemistry (Figure 1). The participants' answers were graded as following: 0, for a wrong answer or no answer; 1, for partial answer; and 2, for a full answer. Figure 1 presents the average scores for each item in the pre- and posttests. The Wilcoxon signed rank test was applied to the overall difference between the average pre- and posttest scores (p < 0.05). Results show that in the posttest the participants achieved average scores quite close to the full answer (maximum). Interestingly, no correlation emerged between the pretest and the posttest scores, that is, the posttest scores are not related to students' preexisting knowledge. The participants were also interviewed and asked to describe their learning experiences during the course. They enthusiastically described what they gained from the course and how it influenced their teaching, as reflected by these comments: Samira: Before I took this course I knew nothing about nanochemistry, except for the fact that nano is very small. I learned a lot during the course but the most exciting part for me was self-learning of a whole new topic in nanotechnology: its history, the chemistry and the physics related to it and its applications... I even told my son that he should specialize in nanotechnology when he grows up. Shir: In school, I told my students about the new topics I learned about during the course, telling them also about the subject I studied in depth. I am now clearly aware that some concepts in nanochemistry were unclear to me even though I was teaching a nano program. Now I feel that I have acquired greater knowledge and deeper understanding in this field.

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1. 2. 3. 4. 5. 6. 7. 8.

11. 12. 13. 14. 15.

Science is not only textbooks. The genuine research work happens in the laboratories, and is described in research journals. In this course we exposed you to the scientific tools


Literature Cited

9. 10.

As reflected from the participants' statements as presented above, the goals set for the course were fully achieved. The course provided them with the basic tools and knowledge to become nanoliterate. I end this paper quoting Reshef Tenne when he summarized the course:

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I am especially grateful to Reshef Tenne for his professionalism and kindness and for many hours of guidance. I am also grateful to the scientists who took part in this project including: Leeor Kronik (teaching the first module); Hagai Cohen (XPS); Yishai Feldman (XRD); Sidney R. Cohen (STM, AFM); Konstantin Gartsman (SEM); Eyal Shimoni (SEM); Ronit Popovitz-Biro (TEM); Gregory Leitus (transport measurements); XiaoMeng Sui and Noa Lachman (Daniel H. Wagner's research lab experiment: Electrospinning Nanotubes Reinforced Composites); and Nitzan Shadmi and Tohar Yarden (Ernesto Joselevich's research lab experiment: Drawing with Nanotubes). The course is part of the Rothschild-Weizmann program for Excellence in Science Teaching and was supported by the Rothschild-Caesarea Foundation.

16. 17.

Roco, M. C. J. Nanopart. Res. 2001, 3, 5. Roco, M. C. Nat. Biotechnol. 2003, 21, 1247. Walters, K. A.; Bullen, H. A. J. Chem. Educ. 2008, 85, 1406. Samet, C. J. Nano Educ. 2009, 1, 15. Porter, L. A. J. Chem. Educ. 2007, 84, 259. Ambrogi, P.; Caselli, M.; Montaltic, M.; Venturic, M. Chem. Educ.: Res. Pract. 2008, 9, 5. Drane, D.; Swarat, S.; Light, G.; Hersam, M.; Mason, T. J. Nano Educ. 2009, 1, 8. Tomasik, J. H.; Jin, S.; Hamers, R. J.; Moore, J. W. J. Nano Educ. 2009, 1, 48. Borko, H. Educ. Researcher 2004, 33, 3. Munby, H.; Russell, T.; Martin, A. K. In Handbook of Research on Teaching, 4th ed.; Richardson, V., Ed.; American Educational Research Association: Washington, DC, 2001; p 877. Shulman, L. S. Educ. Researcher 1986, 15, 4. Shulman, L. S. Harv. Educ. Rev. 1987, 57, 1. Ismach, A.; Kantorovich, D.; Joselevich, E. J. Am. Chem. Soc. 2005, 127, 11554–11555. Geblinger, N.; Ismach, A.; Joselevich, E. Nat. Nanotechnol. 2008, 3, 195–200. Vaisman, L.; Wachtel, E.; Wagner, H. D.; Marom, G. Polymer 2007, 48, 6843–6854. Wagner, H. D. Nat. Nanotechnol. 2007, 2, 742-744 (News & Views). Blonder, R. Control of Structure and Function of Biomaterials by External Triggering Signals. Ph.D. Thesis, The Hebrew University of Jerusalem, Israel, 1999.

Supporting Information Available Initial references given to the students as an introduction material for learning of the 14 topics in materials and nanoscience. This material is available via the Internet at http://pubs.acs.org.

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The Story of Nanomaterials in Modern Technology: An Advanced

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